Effects of aripiprazole on subjective and physiological responses to alcohol

"It's been a long time since I drank like that": A case report of binge drinking associated with aripiprazole

Aripiprazole has been linked to the development of impulse control problems (ICPs), most commonly gambling. Aripiprazole's effect on serotonergic and dopaminergic pathways has had mixed results on drinking behaviors. A male patient receiving outpatient psychiatric care presented with ongoing symptoms of depression on his current regimen of mirtazapine and gabapentin. Aripiprazole was chosen for augmentation after multiple failed trials of alternative medications. Within 3 weeks the patient discontinued the medication due to escalating binge-drinking behavior. This behavior resolved within 3 days after discontinuing aripiprazole. Individuals who engage in binge drinking demonstrate consistent impulse control deficits that are unrelated to the rewarding effects of alcohol. Aripiprazole may be related to this patient's return to binge drinking from an ICP standpoint rather than driven by alcohol cravings as other psychosocial factors remained stable throughout this time.

A randomized trial of the effects of COMT inhibition on subjective response to alcohol: Moderation by baseline COMT activity and mediation of alcohol self-administration

BACKGROUND

Poor inhibitory control and enhanced subjective response to alcohol are interrelated risk factors for alcohol use disorder (AUD) that share underlying neural substrates, including dopamine signaling in the right prefrontal cortex, a potential target for pharmacological intervention. Cortical dopamine inactivation is primarily regulated by catechol-O-methyltransferase (COMT), an enzyme with large variation in activity as a function of the COMT rs4680 (val158met) single nucleotide polymorphism. In a previous randomized, placebo-controlled trial of the COMT inhibitor tolcapone (200 mg TID) in non-treatment-seeking participants with AUD, we found that tolcapone, relative to placebo, reduced alcohol self-administration only among rs4680 val-allele homozygotes, whose COMT activity is higher than in met-allele carriers.

METHODS

We conducted secondary analyses of the effects of tolcapone and baseline COMT activity, as indexed by both rs4680 genotype and an enzymatic activity assay, on the subjective response to alcohol in a bar-laboratory paradigm among 60 participants in the previous trial.

RESULTS

Tolcapone did not affect alcohol-induced stimulation or sedation more than placebo. However, baseline COMT activity moderated the effects of the drug on both outcomes, such that tolcapone-treated participants with higher baseline COMT activity had less stimulation (p = 0.008) and sedation (p = 0.053) than participants with lower baseline COMT activity and those treated with placebo. Additionally, alcohol-induced stimulation significantly mediated the interacting effects of baseline COMT activity and tolcapone on bar-laboratory self-administration.

CONCLUSIONS

Tolcapone may reduce subjective response to alcohol more effectively among individuals with preexisting high COMT activity an effect that could account for the drug's reduction of alcohol consumption among these individuals.

Novel Agents for the Pharmacological Treatment of Alcohol Use Disorder

Alcohol use disorder (AUD) is a highly prevalent but severely under-treated disorder, with only three widely-approved pharmacotherapies. Given that AUD is a very heterogeneous disorder, it is unlikely that one single medication will be effective for all individuals with an AUD. As such, there is a need to develop new, more effective, and diverse pharmacological treatment options for AUD with the hopes of increasing utilization and improving care. In this qualitative literature review, we discuss the efficacy, mechanism of action, and tolerability of approved, repurposed, and novel pharmacotherapies for the treatment of AUD with a clinical perspective. Pharmacotherapies discussed include: disulfiram, acamprosate, naltrexone, nalmefene, topiramate, gabapentin, varenicline, baclofen, sodium oxybate, aripiprazole, ondansetron, mifepristone, ibudilast, suvorexant, prazosin, doxazosin, N-acetylcysteine, GET73, ASP8062, ABT-436, PF-5190457, and cannabidiol. Overall, many repurposed and novel agents discussed in this review demonstrate clinical effectiveness and promise for the future of AUD treatment. Importantly, these medications also offer potential improvements towards the advancement of precision medicine and personalized treatment for the heterogeneous AUD population. However, there remains a great need to improve access to treatment, increase the menu of approved pharmacological treatments, and de-stigmatize and increase treatment-seeking for AUD.

Medication Development for Alcohol Use Disorder: A Focus on Clinical Studies

Compared to other medical disorders, including other brain diseases, the number of medications approved for alcohol use disorder (AUD) is very small. Disulfiram, naltrexone (oral and long-acting), and acamprosate are approved by the US Food and Drug Administration (FDA) to treat patients with AUD. These medications are also approved in other countries, including in Europe, where the European Medicines Agency (EMA) also approved nalmefene for AUD. Furthermore, baclofen was recently approved for AUD in France. These approved medications have small effect sizes, which are probably the consequence of the fact that they only work for some patients, yet a personalized approach to match the right medication with the right patient is still in its infancy. Therefore, research is needed to expand the armamentarium of medications that clinicians can use to treat their patients, as well as to better develop personalized approaches. This book chapter reviews other medications, beyond those approved by the FDA, that have shown efficacy in clinical trials, as well as medications which are still in the early stages of evaluation in human studies.

Dopaminergic Genetic Variation Influences Aripiprazole Effects on Alcohol Self-Administration and the Neural Response to Alcohol Cues in a Randomized Trial

Dopamine (DA) signaling regulates many aspects of Alcohol Use Disorder (AUD). However, clinical studies of dopaminergic medications, including the DA partial agonist aripiprazole (APZ), have been inconsistent, suggesting the possibility of a pharmacogenetic interaction. This study examined whether variation in DA-related genes moderated APZ effects on reward-related AUD phenotypes. The interacting effects of APZ and a variable number tandem repeat (VNTR) polymorphism in DAT1/SLC6A3 (the gene encoding the DA transporter (DAT)) were tested. In addition, interactions between APZ and a genetic composite comprising the DAT1 VNTR and functional polymorphisms in catechol-O-methyltransferase (COMT), DRD2, and DRD4 were evaluated. Ninety-four non-treatment-seeking individuals with AUD were genotyped for these polymorphisms, randomized to APZ (titrated to 15 mg) or placebo for 8 days, and underwent an fMRI alcohol cue-reactivity task (day 7; n=81) and a bar lab paradigm (day 8). Primary outcomes were alcohol cue-elicited ventral striatal (VS) activation and the number of drinks consumed in the bar lab. DAT1 genotype significantly moderated medication effects, such that APZ, relative to placebo, reduced VS activation and bar-lab drinking only among carriers of the DAT1 9-repeat allele, previously associated with lower DAT expression and greater reward-related brain activation. The genetic composite further moderated medication effects, such that APZ reduced the primary outcomes more among individuals who carried a larger number of DAT1, COMT, DRD2, and DRD4 alleles associated with higher DA tone. Taken together, these data suggest that APZ may be a promising AUD treatment for individuals with a genetic predisposition to higher synaptic DA tone.

Advances in Pharmacotherapy Development: Human Clinical Studies

For more than 25 years, researchers have made advances in developing medications to treat alcohol use disorder (AUD), highlighted by the US Food and Drug Administration's (FDA's) approval of disulfiram, naltrexone (oral and long-acting), and acamprosate. These medications are also approved in Europe, where the European Medicines Agency (EMA) recently added a fourth medication, nalmefene, for AUD. Despite these advances, today's medications have a small effect size, showing efficacy for only a limited number of individuals with AUD. However, a host of new medications, which act on variety of pharmacologic targets, are in the pipeline and have been evaluated in numerous human studies. This article reviews the efficacy and safety of medications currently being tested in human trials and looks at ongoing efforts to identify candidate compounds in human studies. As mentioned in the National Institute on Alcohol Abuse and Alcoholism's Strategic Plan 2017-2021 ( https://www.niaaa.nih.gov/sites/default/files/StrategicPlan_NIAAA_optimized_2017-2020.pdf ), medications development remains a high priority. By developing more effective and safe medications, and identifying those patients who will benefit the most from these treatments, we can provide clinicians with the tools they need to treat this devastating disorder, providing relief for patients and their families and markedly improving public health and safety.

Aripiprazole Suppression of Drinking in a Clinical Laboratory Paradigm: Influence of Impulsivity and Self-Control

BACKGROUND

Aspects of impulsivity have been implicated in the development, or maintenance, of alcohol use disorder (AUD). The brain dopamine system is implicated in both reward processing/memory (typically subcortical) and in brain inhibitory control mechanisms (typically cortical). Using a validated clinical laboratory paradigm, the dopamine/serotonin "stabilizing" drug, aripiprazole was evaluated in non-treatment-seeking AUD individuals based on their level of impulsivity/self-control.

METHODS

Ninety-nine individuals (77% male; mean age 27; 7.5 drinks per day; 83% heavy drinking days) meeting DSM-IV criteria for alcohol dependence were randomized to aripiprazole (N = 47 evaluable) or placebo (N = 48 evaluable) based on their Barratt Impulsiveness Scale (BIS-11) score (above or below 68). Aripiprazole, or similar placebo, was titrated to 15 mg over 8 days. Drinking was recorded over 6 days under natural conditions. On Day 8, after 1 day of required abstinence, individuals participated in a bar laboratory paradigm that included a priming drink (breath alcohol concentration [BAC] target 0.02 to 0.03 g/dl) and free-choice consumption of up to 8 drinks (max BAC 0.1 g/dl) in exchange for a "bar credit" of $2 per drink (max $16). End points were drinks per day under natural conditions and drinks consumed in the bar laboratory after the priming drink.

RESULTS

There was no significant main effect of aripiprazole or interaction with BIS-11 score during the natural drinking period. However, there was a main effect of aripiprazole on bar laboratory drinking (p = 0.04) and aripiprazole reduced the total number of drinks consumed more among individuals with low self-control (p = 0.034) and increased latency to consume those drinks (p = 0.045) more among those with high impulsivity. Relative to placebo, aripiprazole caused more side effects and increased alcohol-induced sedation, but neither significantly influenced its interaction with impulsivity/self-control scores on drinking.

CONCLUSIONS

This paradigm forced a choice between immediate drinking reward and delayed monetary reward. In those with high impulsivity and/or low self-control, aripiprazole shifts the balance away from immediate drinking toward a later reward. Medications targeting cortical dopamine/serotonin balance might show clinical benefit of reduced drinking, among individuals with impulsivity/low self-control.

Dose specific effects of olanzapine in the treatment of alcohol dependence

RATIONALE

It is well established that the rewarding effects of alcohol are modulated by the mesolimbic dopaminergic system. Olanzapine, a D2 dopamine antagonist, has been shown to reduce alcohol craving and consumption.

OBJECTIVE

To clarify whether olanzapine has clinical utility in the treatment of alcohol dependence, a 12-week, double-blind, and randomized clinical trial was conducted.

METHODS

One hundred twenty-nine treatment-seeking alcohol-dependent adults were randomly assigned to 12 weeks of olanzapine (5 vs. 2.5 mg) or placebo. Outcomes examined were average drinks per drinking day (DDD), proportion of drinking days (PDD) to total days in treatment, alcohol craving, and impaired control over alcohol use. Mixed models were used to examine medication effects during the course of treatment on specified outcomes.

RESULTS

All of the analyses indicated a main effect for time, such that there were reductions in alcohol use and craving and an increase in control over alcohol use across treatment conditions. Dose-response analyses indicated that, in comparison to placebo, participants in the 5 mg group experienced reduced craving for alcohol and participants in the 2.5 mg group decreased in PDD and increased in their control over alcohol use. Better control over alcohol use remained significant 6 months post-treatment for the 2.5 mg group. Subjective experiences of the medication suggest that 2.5 and 5 mg were equally well tolerated.

CONCLUSIONS

Results provide some support for the notion that dosage is an important consideration in relation to effectiveness; however, the cost-benefit balance does not support the clinical utility of olanzapine in treating alcohol dependence.

Neurochemical mechanisms of alcohol withdrawal

Alcohol dependence encompasses a serious medical and societal problem that constitutes a major public health concern. A serious consequence of dependence is the emergence of symptoms associated with the alcohol withdrawal syndrome when drinking is abruptly terminated or substantially reduced. Clinical features of alcohol withdrawal include signs of central nervous system hyperexcitability, heightened autonomic nervous system activation, and a constellation of symptoms contributing to psychologic discomfort and negative affect. The development of alcohol dependence is a complex and dynamic process that ultimately reflects a maladaptive neurophysiologic state. Perturbations in a wide range of neurochemical systems, including glutamate, γ-aminobutyric acid, monoamines, a host of neuropeptide systems, and various ion channels produced by the chronic presence of alcohol ultimately compromise the functional integrity of the brain. These neuroadaptations not only underlie the emergence and expression of many alcohol withdrawal symptoms, but also contribute to enhanced relapse vulnerability as well as perpetuation of uncontrolled excessive drinking. This chapter highlights the hallmark features of the alcohol withdrawal syndrome, and describes neuroadaptations in a wide array of neurotransmitter and neuromodulator systems (amino acid and monoamine neurotransmitter, neuropeptide systems, and various ion channels) as they relate to the expression of various signs and symptoms of alcohol withdrawal, as well as their relationship to the significant clinical problem of relapse and uncontrolled dangerous drinking.

Treatment for comorbid borderline personality disorder and alcohol use disorders: a review of the evidence and future recommendations

There is a high degree of comorbidity between borderline personality disorder (BPD) and alcohol use disorders (AUDs). There is some evidence that this pattern of comorbidity may be associated with poorer prognosis. Although there are many different psychotherapeutic and pharmacological treatments for BPD and AUDs when they occur alone, there are very few treatment options when they occur together. The objective of this article was to review the existing treatment options-both psychotherapeutic and pharmacological-for patients with dual diagnoses of BPD and AUDs and to explore alternative treatment options that warrant further study. There have been a number of studies that have examined the efficacy of specific psychotherapies targeting drinking among patients with comorbid BPD; however, their efficacy in reducing BPD symptoms is unknown. There are also three psychotherapies that were specifically developed for patients with BPD and substance use disorders (SUDs), but only one of these (Dynamic Deconstructive Psychotherapy) has been tested among patients with dual diagnoses of BPD and AUDs. Research on pharmacotherapy for dual diagnoses of BPD and AUD is scarce, and no study has yet explored medication options that can concurrently manage symptoms of BPD and decrease alcohol consumption. Interestingly, there is growing evidence that anticonvulsants and second generation antipsychotics, the recent medications of choice for the management of BPD symptoms, may also reduce alcohol craving and consumption. Although premature, these findings are encouraging especially for this population of patients for whom treatment options are very limited.

A double-blind, placebo-controlled trial to assess the efficacy of quetiapine fumarate XR in very heavy-drinking alcohol-dependent patients

BACKGROUND

Despite advances in developing medications to treat alcohol dependence, few such medications have been approved by the Food and Drug Administration. Identified molecular targets are encouraging and can lead to the development and testing of new compounds. Atypical antipsychotic medications have been explored with varying results. Prior research suggests that the antipsychotic quetiapine may be beneficial in an alcohol-dependent population of very heavy drinkers.

METHODS

In this double-blind, placebo-controlled trial, 224 alcohol-dependent patients who reported very heavy drinking were recruited across 5 clinical sites. Patients received either quetiapine or placebo and Medical Management behavioral intervention. Patients were stratified on gender, clinical site, and reduction in drinking prior to randomization.

RESULTS

No differences between the quetiapine and placebo groups were detected in the primary outcome, percentage heavy-drinking days, or other drinking outcomes. Quetiapine significantly reduced depressive symptoms and improved sleep but had no effect on other nondrinking outcomes. Results from a subgroup analysis suggest that patients who reduced their drinking prior to randomization had significantly better drinking outcomes during the maintenance phase (p < 0.0001). No significant interactions, however, were observed between reducer status and treatment group. Finally, quetiapine was generally well tolerated. Statistically significant adverse events that were more common with quetiapine versus placebo include dizziness (14 vs. 4%), dry mouth (32 vs. 9%), dyspepsia (13 vs. 2%), increased appetite (11 vs. 1%), sedation (15 vs. 3%), and somnolence (34 vs. 9%).

CONCLUSIONS

This multisite clinical trial showed no efficacy for quetiapine compared with placebo at reducing alcohol consumption in heavy-drinking alcohol-dependent patients.

Attenuation of reinforcing and psychomotor stimulant effects of amphetamine by aripiprazole

Partial dopamine agonists are potential medications for the treatment of amphetamine addiction. They have been hypothesized to stabilize the dopamine system by acting as antagonists during high dopaminergic tone resulting from amphetamine use and as agonists during withdrawal. Aripiprazole is an atypical antipsychotic that acts as a partial D2 dopamine and a serotonin 5-HT₁(A) agonist and a serotonin 5-HT₂(A) antagonist. The aim of the present study was to examine the effects of aripiprazole on behaviors induced and maintained by d-amphetamine. To this end, intravenous d-amphetamine self-administration [fixed ratio 3 (FR3) schedule, 0.02 mg/infusion] and d-amphetamine-induced (0, 1.5 mg/kg intraperitoneally) locomotor activity, as well as spontaneous locomotor activity and sucrose pellet selfadministration (FR3 schedule) were studied in male Wistar rats after aripiprazole (0, 0.3, 1, 3 mg/kg i.p.) administration. Aripiprazole pre-treatment resulted in bidirectional effects on amphetamine self-administration. The 1 mg/kg dose increased, and the highest dose decreased the number of amphetamine infusions. In the locomotor activity experiments, aripiprazole attenuated amphetamine-induced activity dose-dependently and tended to suppress spontaneous activity. The highest aripiprazole doses decreased also sucrose pellet self-administration. The increase in amphetamine self-administration with the intermediate aripiprazole dose, as well as the decrease in amphetamine-induced locomotor activity, suggests that aripiprazole acted as a dopamine antagonist. Suppression of amphetamine and sucrose self-administration by the highest aripiprazole dose was probably caused by non-specific effects. Together, these results indicate that under conditions of dopaminergic stimulation, aripiprazole attenuates the reinforcing and psychomotor stimulant effects of d-amphetamine, but the dose range for this effect is rather limited.

The dopamine hypothesis of drug addiction and its potential therapeutic value

Dopamine (DA) transmission is deeply affected by drugs of abuse, and alterations in DA function are involved in the various phases of drug addiction and potentially exploitable therapeutically. In particular, basic studies have documented a reduction in the electrophysiological activity of DA neurons in alcohol, opiate, cannabinoid, and other drug-dependent rats. Further, DA release in the Nucleus accumbens (Nacc) is decreased in virtually all drug-dependent rodents. In parallel, these studies are supported by increments in intracranial self stimulation (ICSS) thresholds during withdrawal from alcohol, nicotine, opiates, and other drugs of abuse, thereby suggesting a hypofunction of the neural substrate of ICSS. Accordingly, morphological evaluations fed into realistic computational analysis of the medium spiny neuron of the Nacc, post-synaptic counterpart of DA terminals, show profound changes in structure and function of the entire mesolimbic system. In line with these findings, human imaging studies have shown a reduction of dopamine receptors accompanied by a lesser release of endogenous DA in the ventral striatum of cocaine, heroin, and alcohol-dependent subjects, thereby offering visual proof of the "dopamine-impoverished" addicted human brain. The lasting reduction in physiological activity of the DA system leads to the idea that an increment in its activity, to restore pre-drug levels, may yield significant clinical improvements (reduction of craving, relapse, and drug-seeking/taking). In theory, it may be achieved pharmacologically and/or with novel interventions such as transcranial magnetic stimulation (TMS). Its anatomo-physiological rationale as a possible therapeutic aid in alcoholics and other addicts will be described and proposed as a theoretical framework to be subjected to experimental testing in human addicts.

Preclinical evidence of new opioid modulators for the treatment of addiction

IMPORTANCE OF THE FIELD

Addiction to opiates is one of the most severe forms of substance dependence, and despite a variety of pharmacological approaches to treat it, relapse is observed in a high percentage of subjects. New pharmacological compounds are necessary to improve the outcome of treatments and reduce adverse side effects. Moreover, drugs that act on the opioid system can also be of benefit in the treatment of alcohol or cocaine addiction. AREA COVERED BY THIS REVIEW: Recent preclinical studies of pharmacological agents for the treatment of opiate addiction (2008 to the present date).

WHAT THE READER WILL GAIN

The reader will be informed of the latest drugs shown in animal models to modify dependence on opiates and the reinforcing effects of these drugs. In addition, reports of the latest studies to test these compounds in models of other drug addictions are reviewed.

TAKE HOME MESSAGE

The classic clinical pharmacotherapy for opiate dependence, involving mu-opioid receptor agonists or antagonists, has not yielded a high success rate in humans. In pharmacotherapy for opioid dependence, new options are emerging and different pharmacological strategies are now being tested.

Subjective responses to alcohol consumption as endophenotypes: advancing behavioral genetics in etiological and treatment models of alcoholism

Individual differences in subjective responses to alcohol consumption represent genetically mediated biobehavioral mechanisms of alcoholism risk (i.e., endophenotype). The objective of this review is three-fold: (1) to provide a critical review the literature on subjective response to alcohol and to discuss the rationale for its conceptualization as an endophenotype for alcoholism; (2) to examine the literature on the neurobiological substrates and associated genetic factors subserving individual differences in subjective response to alcohol; and (3) to discuss the treatment implications of this approach and to propose a framework for conceptualizing, and systematically integrating, endophenotypes into alcoholism treatment.

Long-term treatment with aripiprazole on the waking and postprandial urges to smoke in Chinese heavy smokers

The central dopaminergic system plays a critical role in the reinforcing effects of nicotine, which are key determinants in the urge to smoke. Previous study has demonstrated that immediate administration of 10-mg aripiprazole significantly decreased various subjective responses to smoking. The present study investigated whether 2-week treatment with 10-mg aripiprazole could attenuate waking and postprandial urges to smoke in Chinese male and female heavy smokers. A randomized and placebo-controlled pilot clinical study was conducted to assess the effect of aripiprazole on various responses to smoking. The primary outcomes were subject's ratings on questionnaires of smoking urge, withdrawal syndromes, and cigarette evaluation. All participants were administered either placebo or 10-mg aripiprazole for 2 weeks. Throughout the experiment, participants were required to self-report (1) smoking urge and nicotine withdrawal symptoms before their first cigarette after awakening and after lunch and (2) subjective responses to the first cigarette smoked of the day and after lunch. Aripiprazole was associated with significantly decreased waking and postprandial urges to smoke. Aripiprazole failed to produce a significant effect on overall nicotine withdrawal symptoms after awakening and after lunch. However, waking, but not postprandial, withdrawal craving and syndromes were significantly reduced by aripiprazole. Aripiprazole had no effect on the overall subjective responses to the first cigarette of the day and after lunch. The attenuating effects of aripiprazole on waking and postprandial urges to smoke demonstrate the promising effect of aripiprazole in the treatment of nicotine dependence.

The effect of aripiprazole on cue-induced brain activation and drinking parameters in alcoholics

Because the effects of alcohol and its environmental cues on brain dopamine have been implicated in the maintenance of heavy drinking, drugs that modify dopamine might be useful in reducing drinking or promoting abstinence. The goal of the current study was to use an established brain imaging paradigm to explore the effect of aripiprazole (final dose 15 mg over a 14-day period), a dopamine stabilizer medication, on alcohol cue-induced brain activation and drinking in alcoholics. Non-treatment-seeking alcoholics were randomly assigned aripiprazole (n = 14) or identical placebo (n = 16) and reported their alcohol use while taking study medication for 14 days before an alcohol cue-induced brain functional magnetic resonance imaging study. In a Philips 3.0-T magnetic resonance imaging scanner, subjects were given a sip of alcohol before viewing a randomized presentation alcoholic- and nonalcoholic-beverage photographs while subjects rated their urge to drink. During photograph presentation, changes in regional brain activity were measured, and differences between viewing alcoholic beverage and nonalcoholic beverages were compared within and between groups. Brain activity analysis revealed increased activation for placebo-treated subjects in the right ventral striatum (P < 0.005; threshold 15 voxels), while there was a blunting of activation in this area in the aripiprazole-treated subjects. Aripiprazole-treated subjects, compared with placebo-treated subjects, also had significantly less heavy drinking during the 14-day medication period. The study provides both novel and valuable information regarding the effect of aripiprazole on cue-induced brain activation and voluntary drinking during treatment.

A safety and tolerability laboratory study of the combination of aripiprazole and topiramate in volunteers who drink alcohol

OBJECTIVE

There are no reports examining the safety of taking both topiramate and aripiprazole together with alcohol. The ultimate aim for this research is to determine whether this combination is safe and is superior to either drug taken alone in reducing alcohol use in alcohol dependent patients.

METHOD

This was an open-label trial. Thirteen heavy drinking participants not seeking treatment for alcoholism were randomized. Participants were titrated up to 300 mg of topiramate and 30 mg of aripiprazole a day over 35 days. Participants reported adverse events (AEs) daily alcohol use and participated in an alcohol challenge session (ACS).

RESULTS

The eight participants who completed the study achieved the maximum doses of drugs. The AEs of the drugs would suggest that the AEs profile is broader but not additive. Alcohol use from the 28 days before screening to the seven days before the ACS was reduced (p = 0.08).

CONCLUSION

There was no evidence that AEs of aripiprazole and topiramate are additive and can, therefore, be administered safely together with a modest amount of alcohol. There was also a trend for a reduction of alcohol use by participants. This finding has implications for further investigation of this combination of drugs for alcohol dependence.

Efficacy and safety of aripiprazole in the treatment of bipolar disorder: a systematic review

BACKGROUND

The current article is a systematic review concerning the efficacy and safety of aripiprazole in the treatment of bipolar disorder.

METHODS

A systematic Medline and repositories search concerning the usefulness of aripiprazole in bipolar disorder was performed, with the combination of the words 'aripiprazole' and 'bipolar'.

RESULTS

The search returned 184 articles and was last updated on 15 April 2009. An additional search included repositories of clinical trials and previous systematic reviews specifically in order to trace unpublished trials. There were seven placebo-controlled randomised controlled trials (RCTs), six with comparator studies and one with add-on studies. They assessed the usefulness of aripiprazole in acute mania, acute bipolar depression and during the maintenance phase in comparison to placebo, lithium or haloperidol.

CONCLUSION

Aripiprazole appears effective for the treatment and prophylaxis against mania. The data on bipolar depression are so far negative, however there is a need for further study at lower dosages. The most frequent adverse effects are extrapyramidal signs and symptoms, especially akathisia, without any significant weight gain, hyperprolactinaemia or laboratory test changes.

Aripiprazole blocks reinstatement but not expression of morphine conditioned place preference in rats

Aripiprazole is an atypical antipsychotic drug primarily characterized by partial agonist activity at dopamine(DA) D2 receptors and serotonin-1A (5-hydroxytryptamine, 5-HT1A) receptors and minimal side effects.Based on its pharmacological profile, including stabilization of mesocorticolimbic DA activity (a pathway implicated in drug addiction), we investigated the effects of aripiprazole on relapse to morphine seeking in rats. In experiment 1, rats underwent morphine-induced conditioned place preference (CPP) training with alternate injections of morphine (5 mg/kg, s.c.) and saline (1 ml/kg, s.c.) for 8 consecutive days. To examine the effect of aripiprazole on the expression of morphine-induced CPP, rats received aripiprazole (0, 0.03, 0.1,and 0.3 mg/kg, i.p.) 30 min before testing for the expression of CPP. In experiment 2, rats underwent the same CPP training as in experiment 1 and subsequent extinction training. To examine the effect of aripiprazole on reinstatement of morphine-induced CPP, rats received aripiprazole 30 min before testing for reinstatement of CPP. In experiment 3, to assess the effects of aripiprazole on locomotor activity, aripiprazole was administered 30 min before testing for locomotor activity. Aripiprazole significantly decreased the reinstatement of CPP induced by a priming injection of morphine but had no effect on the expression of morphine-induced CPP or locomotor activity. The D2 and 5-HT1A partial agonist and 5-HT2A antagonist properties of aripiprazole likely account for the blockade of relapse to drug seeking. These findings suggest that aripiprazole may have therapeutic value for reducing craving and preventing relapse to drug seeking.

Subjective, cognitive/psychomotor, and physiological effects of aripiprazole in Chinese light and heavy smokers

BACKGROUND

Drug addiction researchers have begun to study dopamine partial agonists as potential therapeutic agents. The partial dopamine D(2) receptor agonist aripiprazole has recently been tested as a treatment for stimulant and alcohol dependence in both animal and clinical studies.

METHODS

A randomized and placebo-controlled pilot clinical study was conducted in a population of Chinese light and heavy smokers to assess the effect of aripiprazole on various responses to smoking. The primary outcomes were subject's ratings on questionnaires of smoking urge, withdrawal syndromes, and cigarette evaluation. Placebo, 5, and 10mg aripiprazole were acutely administered in all participants, with administrations at least 7 days apart. Subjective responses to a smoked cigarette, working memory, and attention/psychomotor performance were assessed before and after drug administration in each experimental session. Abstinence-induced smoking urge, withdrawal symptoms, blood pressure, and heart rate were also measured every 45 min after drug administration. Finally, a cue-testing session was carried out 4h after each drug administration.

RESULTS

Administration of 10mg aripiprazole significantly decreased both the subjective response and psychological reward derived from smoking a cigarette in heavy smokers. While neither 5 nor 10mg aripiprazole significantly decreased abstinence-induced smoking urges or withdrawal symptoms in light and heavy smokers, these doses substantially attenuated drug cue-induced smoking urges in heavy smokers. Aripiprazole did not affect working memory or attention/psychomotor performance.

CONCLUSIONS

Light and heavy smokers responded differently to aripiprazole across various dependent measures. Aripiprazole may potentially affect various subjective responses to smoking in heavy smokers.

Aripiprazole effects on alcohol consumption and subjective reports in a clinical laboratory paradigm--possible influence of self-control

INTRODUCTION

There has been increasing interest in the use of medications that affect the dopamine receptor in the treatment of alcoholism. Aripiprazole has the unique pharmacology of being a partial dopamine agonist serving to stabilize brain dopamine systems in both frontal cortical and subcortical areas. As such, it might act to dampen alcohol reinforcement and craving and/or alter control over alcohol use. The current clinical laboratory study was conducted to evaluate the safety and efficacy of aripiprazole as a potential agent to alter drinking and objective effects of alcohol.

METHODS

Thirty nontreatment seeking alcoholics were enrolled in a subacute human laboratory study and received double-blind treatment with up to 15 mg of aripiprazole (n = 15) or identical placebo (n = 15) for 8 days. Tolerability and utility of aripiprazole was monitored during natural drinking over the first 6 days of medication treatment and also during a free choice limited access alcohol consumption paradigm following an initial drink of alcohol in a bar-lab setting on Day 8.

RESULTS

Aripiprazole was well tolerated and reduced drinking in nontreatment seeking alcoholics over 6 days of natural drinking--especially in those with lower self control (more impulsive). It also reduced drinks in the bar-lab after a priming drink and broke the link between priming drink induced stimulation and further drinking. During the bar-lab drinking session, there were no differences in subjective high, intoxication, or craving between subjects treated with aripiprazole or placebo.

DISCUSSION

This study joins several others in demonstrating the utility of subacute dosing laboratory paradigms for evaluating medication effects in alcoholics. Aripiprazole was well tolerated and lowered alcohol use, especially in those with lower impulse control. Further study is needed to determine the safety and utility of aripiprazole in the treatment of alcoholism and if subgroups of alcoholics are more likely to respond.

Treatment implications: using neuroscience to guide the development of new pharmacotherapies for alcoholism

Developing pharmacotherapies to treat alcohol dependence and associated health problems traditionally has been based on gaining a better understanding of the neuroscience underlying alcohol-drinking behavior. To date, three medications have been approved for the treatment of alcohol dependence: disulfiram (Antabuse®), naltrexone (Revia®, Vivitrol®, and Naltrel®), and acamprosate (Campral®). However, these medications have modest efficacy, and there is a great need for newer medications that target different neurochemical systems and which could be used either as adjunctive treatments or to treat subpopulations of drinkers. Furthermore, it also is important to improve current treatment options by understanding and incorporating differences in how people with certain genes respond to medication (i.e., pharmacogenetic differences).